Metallic window screen



July 9, 1940. A. LANG METALLIC WINDOW SCREEN Filed Dec. 16, 1958 Eli-7.

7 INVENTOR.

v NEY Patented July 9, 1940 UNITED STATES PATENT OFFICE 3 Claims.

The present invention relates to improvements in metallic window screens and more particularly to an improved one piece metallic frame which can be constructed from a continuous strip of metal.

An object of the invention is to provide a metallic frame for window screens of novel construction in which the frame is formed from a continuous strip of relatively thin metal and reinforced in an effective manner at its weak points in a new and novel manner.

Another object of the invention is to provide a strong and inexpensive channeled metal frame for screens in which the side walls of the channel are rolled in a new and novel manner to protect the screen and also provide an improved form of frame engaging surface around the outer portion of the frame which will reinforce the outer wall of the channel and improve the appearance of the screen.

Another object of the invention is to provide a metallic frame for window screens of the type having a channel into which the screen fabric is secured by a spline and having a re-entrant reinforcing flange along the outside edge of the channel to provide a continuous window frame engaging surface which extends around the frame and the corners thereof.

For a better understanding of the invention reference should be had to'the accompanying drawing wherein there is shown by way of illustration and not of limitation fragmentary parts of a complete screen constructed in accordance with the invention and several modified forms of 35 frame sections.

In the drawing;

Figure 1 is a fragmentary outside view of a window screen taken at a corner and having the screen fabric and securing spline applied thereto,

Figure 2 is a view similar to Figure 1 showing the inside surface at the corner of a screen constructed in accordance with the invention,

Figure 3 is a vertical, sectional view of a casement window frame with a screen constructed in accordance with the invention applied thereto,

Figure 4 is a fragmentary perspective view showing the cross-section of the screen frame forming strip illustrated in the preceding figures of the drawing, and I 50 Figures 5, 6 and 7 are fragmentary perspective views showing the cross-section of modified shapes which the frame forming strip may take without departing from the spirit of the invention.

In the formation of metallic frames ofthe type contemplated by this invention, it is desirable that the finished frame be free of sharp edges, particularly along the surface of the screen that engages a window frame or like support. also important that the window frame engaging surface have some area in order that a marking of the window frame be avoided when the screen is clamped thereupon. Where the frame is formed from a continuous strip with mitre cuts at the corners, as is also contemplated by this invention, it is also important that the outer wall of the frame be reinforced at the mitred corners.

In my prior U. S. Patent No. 2,094,991, of Octoher 5, 1937, I have illustrated a metallic screen frame in which the outer wall of the frame is reinforced by an outwardly extending flange that extends around the corners of the frame and while this construction provides a smooth and continuous window frame engaging surface upon the frame and also a reinforcing at the corners of the frame, it has been found that unless the metal strip from which the frame is formed is properly chosen with respect to ductility, the outer flange often cracks and/or becomes otherwise ruptured so that the continuity of the flange becomes interrupted and its reinforcing function is thereby destroyed. In order to overcome this objection, the present invention contemplates the provision of an inwardly projecting flange along the outer edge of the frame which will form a continuous surface around the corners of the screen frame. By providing such an inwardly extending flange of involute bending at the edge of the outer wall of the screen frame, all tendency for the reinforcing flange to break is avoided when the frame forming strip is bent at the mitred corners. This is due to the fact that the inwardly extending flange tends to draw inwardly over the apex of the mitre cuts where, due to the rounded character of the spline customarily used with screens of this character, it does not interfere with the insertion of the spline or screen securing rod.

Another important advantage provided by the present invention is that because of the outward and'inward involute rolling at the edge of the outer channel wall the screen frame has a smooth artistically appearing exterior which greatly enhances its appearance when applied to a window frame and at the same time the outer wall of the frame, due to the nature of this bending, is considerably stronger and stiffer than are screen frames of the type shown in my prior patent, wherein the'outer wall'of the" channel is provided with a simple outwardly extending flange.

As illustrated in Figures 1, 2 and 3 of the drawing, the frame constructed in accordance with this invention comprises a continuous strip of steel bent or folded to form a channel-like portion ill into which the edges of a screen fabric ll may be secured and at points corresponding to the corners of a finished frame the strip thus folded is provided with mitre cuts l2 that extend through the inner wall and bottom of the channel-like portion. After the strip of steel has thus been folded and provided with the mitre cuts l2 the frame can be formed by a bending of the strip on the uncut outer wall of the channel-like portion at the apex of the mitre cuts as at l3. This will bring the adjacent sides and ends of the frame into right angled relation with each other and provide a continuous channel about the corners of the frame. After the frame is thus formed a spline I4 having a right angled bend or bends corresponding to the corners of the frame will be placed over the channel-like recess of the frame with the edge of the screen fabric and pressed in to thus secure the screen fabric ll upon the frame. In order to protect the screen fabric II against damage and/or breaking, the inner wall of the channel-like portion ll) of the frame is provided with a beading l5 over which the screen fabric II will be drawn and tightened as the spline i4 is forced into the channel-like portion of the frame. This beading l5 in addition to providing a smooth and rounded surface over which the screen fabric H can be drawn also serves to stiffen and reinforce the inner wall of the channel-like portion of the frame. In order to stiffen and reinforce the outer wall of the channel and at the same time provide a neat appearing and a stronger frame than is possible with a single outwardly extending flange the. edge of the outer wall of the channel-like portion In of the frame is provided with an outwardly and inwardly rolled beading H; which, as-will hereinafter appear, may or may not be closed upon itself. In its simplest form this beading may comprise nothing more than an outward flaring portion H in the outer wall which terminates as an inwardly extending flange 18 at the outer edge of the screen as is shown in Figure .4 of the drawing.

With the above described arrangement it will be seen that when the folded and mitre cut strip has been bent as suggested above, the bend in the outer wall. of the channel-like portion ID will be substantially square while at the same time the inwardly disposed flange It will draw inwardly during the bending operation without being subjected to any breaking stress. And, therefore, as distinguished from the prior art screen frames having. an outwardly extending flange there will'be no tendency for the window frame engaging flange ill to fracture. As illustrated, it will be noted that the .spline H! has a substantially right angled bend which results in a rounded outer contour that will correspond substantially to the curvaturetaken by the window frame engaging flange l8 as it is drawn in during the frame bending operation and as a result the flange 38, even with its inward drawing, will not interfere with the insertion of the spline 14 into the channel-like portion l0 when the screen fabric l l is being applied to the frame.

As illustrated in Figure 3 of the drawing, the major demand for metallic screens of the character contemplated by this invention isin connection with metallic casement windows in which the hinged window or vent is controlled by an operator that extends through the window frame below the permanently affixed screen which is secured upon the inside of the window frame. As here shown, the window frame designated by the numeral I9 is of the well known Z-bar crosssection and the vent designated by the numeral 20 is formed of the same cross-section. The screen, designated in its entirety by the numeral 2|, is shown as positioned upon the inside of the window frame l9 bymeans of brackets 22 at the bottom of the screen and a pivotally mounted retaining latch 23 that may be moved over and into clamping relation with the outside of the frame of the screen 2i. When the screen 2| is thus secured upon the window frame 19 it will be seen that the inwardly extending flange at the outer wall of the channel-like portion l0 forms a smooth and relatively wide bearing surface that provides a smooth and tight fitting engagement between the frame l9 and the frame of the screen 2| and at the same time the screen will present a neat and finished appearance to the entire assembly.

In Figure 5 of the drawing there is shown a further modified form of cross-section for a screen frame in which an inner wall 24 of the channel forming portion of the frame is provided with an outwardly rolled beading 25 over which the screen fabric is drawn when assembled upon the frame. In this embodiment an outer wall 26 of the frame is shown as having an outwardly and angularly bent portion 21 that terminates in an inwardly extending flanged portion 28 that terminates in a re-entrant bent portion 29 which is disposed in line with the outer wall 26 of the channel forming portion of the frame. In this arrangement the bending of the outer wall 25 forms, what might be termed, a closed substantially triangular beading at the outer edge of the screen frame. When the strip is folded in this manner it will be understood that the mitre cuts !2 will be extended through the inner side wall 24 and the bottom of the channel forming portion and terminate with its apex substantially in line with the inside surface of the outer wall 26 of the frame. When so formed the frame can be bent at the corners along the wall 26 and the inwardly disposed portion 29 of the outer reinforcing beading and as a result this beading will provide a continuous window frame engaging surface along the sides and ends and around the corners of the frame.

In Figure 6 of the drawing there is shown a further embodiment of the invention in which an inner wall 30. of the channel forming portion of the-frame is providedwith an outwardly disposed but' inwardlyrolled beading 3! over which the screen fabric may be drawn asabove suggested. .As distinguished from the previously described ,embodiments,.the outer wall designated by the numeral 32 .of the frame forming strip illustrated in this figure of the drawing is provided with an involute beading 33 somewhat similar to the beading 3| upon the inner wall 30 of the frame forming strip except that this beading 33 is somewhat flattened along its outer surface as at 34 to provide a relatively wide and smooth window frame engaging surface. In this embodiment, like those described above, the mitre cut l2 will extend through the inner wall 30 ofthe strip and the bottom of the channel and terminate with its apex in line with the inside surface ofthe outer wall 32 so that when the strip is bent to form a corner of the frame the outer beading 33 and the relatively fiat surface 34 thereof will extend continuously around the corner and provide a complete support engaging surface about the finished frame.

In Figure 7 there is shown a further modiflcation of the invention which is particularly adapted for use in the construction of relatively large and heavy frames. In this embodiment the inner wall designated by the numeral 35 may be provided with any suitable form of beading. As shown, this wall is provided with a beading l 5 similar to that illustrated in Figure 4 of the drawing. This modification of the invention, however, departs materially from the previously described modifications in that the outer wall is formed with a double thickness of material by providing an outer involute beading in the outer side wall as at 36 with a relatively flat portion 31 as a support engaging surface and by folding the remaining portion 38 of the strip inwardly and in parallel engagement with the straight portion of the outer side Wall of the channel forming portion. With this form of strip it will be understood that the mitre cuts l2 will extend through the inner wall 35 and the bottom of the channel forming portion to a point corresponding to the inside surface of the infolded portion 38 of the strip and as a result when the mitred strip is bent to complete the corner of a frame the bend will occur in a double thickness of metal and result in a continuous surface engaging beading about the corners of the finished frame.

While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the specific means disclosed, but may be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and it is desired to claim it so that all such changes as come within the scope of the appended claims are to be considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A metallic frame for window screens of the type employing a rod-like spline for securing a screen fabric thereupon, comprising a continuous strip of sheet metal bent into channel crosssection with a reentrant flange formed along the outside wall of said channel cross-section and having mitre cuts that extend through the inner wall and bottom of said channel cross-section to a point coinciding with the inner edge of said reentrant flange and the outside wall of said channel, said strip being bent at said'mitre cuts to form right angled corners in the frame and said reentrant flange being drawn inwardly at the corners toform a continuous rounded window frame engaging surface at the corners of the frame.

2. A metallic screen supporting frame of the channel type employing a screen fabric securing spline of the character described, comprising a continuous strip of sheet metal bent into channel cross-section and having a reentrant flange along the outer wall thereof extending inwardly in the plane of the frame to a point coincident with the outer wall of said channel cross-section, said continuous strip of sheet metal having mitre cuts at the corners of the frame which extend through the inner wall and bottom of its channel cross-section to a point coincident with the inner edge of said flange and being bent at said mitre cuts to form the corners of the frame, and said reentrant flange being drawn inwardly over said channel cross-section at the mitre cuts to provide an uninterrupted window frame engaging surface about the corners ofthe frame.

3. The method of forming a non-fracturable support engaging surface around the outside of a metallic screen supporting frame of the channel type employing a screen fabric securing spline of the character described, which comprises folding a continuous strip of sheet metal into channel cross-section, forming a. reentrant flange along the outer wall of the channel section by flaring said wall outwardly and flanging the outer edge thereof inwardly in the plane of the frame to a point coincident with the inner wall of said channel cross-section, forming mitre cuts in said channel cross-section which extend through the inner wall and bottom thereof to a point coincident with the inner edge of said flange, and bending said strip at said mitre cuts to form right angled corners while permitting said reentrant flange to draw inwardly during the bending operation, whereby said flange will not be subjected to a rupturing stress during the bending operation.

ALBERT LANG. 

